The present disclosure relates to an image pickup device having a plurality of pixels and an image pickup unit including the image pickup device.
In a typical photographic expression, a technique is known, in which a lens of large diameter having a small F value is used for a photographing optical system, so that a background image is blurred to emphasize a main photographic subject such as a person. However, since the lens of large diameter has a relatively shallow focal depth, accurate focusing is necessary. That is, use of the lens of large diameter tends to cause out-of-focusing, leading to degradation in resolution. In addition, aberration (for example, spherical aberration) of marginal light is often insufficiently corrected in the lens of large diameter. In such a case, original advantages of the large diameter are hard to be fully used.
Under such circumstances, high-frequency components defining a photographed image are extracted for each of colors through the use of axial chromatic aberration occurring in the photographing optical system so that the focal depth is adjusted (for example, see Japanese Unexamined Patent Application Publication No. 2010-81002).